Ancient bone collagen assessment by hand-held vibrational spectroscopy

Radiometric, isotopic, proteomic, and genetic studies of bone collagen are mainstays of archaeometric analysis. All four techniques are destructive and require substantial laboratory, temporal, and financial commitments. Because such analyses are predicated on the presence of a sufficient quantity of unaltered proteins (i.e. collagen), the development and validation of tools for the rapid, non-destructive, in situ analysis of collagen content could yield measurable benefits. In the present work, the results of a preliminary, proof-of-concept study on the utility of four hand-held vibrational spectroscopic instruments, one Fourier-Transform Infrared (FTIR) spectrometer and three Raman spectrometers (two with an excitation wavelength of 785 nm, and one with an excitation wavelength of 1030 nm), for analyzing the collagen content of archaeological bones are described. While the FTIR and 785 nm Raman devices showed little or no ability to discriminate between well- and poorly-preserved bone, the application of hand-held 1030 nm Raman spectroscopy appears to be well-suited for such a task. The ability to detect a measurable and characteristic spectroscopic peak associated with the δCH2 scissoring of Type I collagen in high-yielding, raw bone samples opens the door to the utilization of this technology in field research environments. •Collagen content in ancient bone assessed by hand-held FTIR and Raman.•Goal is identification of field-deployable tools for sample triage.•FTIR and 785 nm Raman devices do not produce useful results.•1030 nm Raman differentiates between well- and poorly preserved collagen

Hand-held Raman spectroscopy as a pre-screening tool for archaeological bone

Bone collagen is the required substrate for a variety of archaeometric analyses, including radiocarbon dating, stable isotope analysis, proteomics, and ancient DNA. Sampling of bone for such analyses is, however, a destructive process, and biomolecular extraction is a time-, labor-, and capital-intensive process. As such, the ability to pre-screen bone for potential collagen level in the field (or in remote museums, storage repositories, or other deployed and austere environments) for archaeological and forensic purposes is highly desirable. Building on previous assessments of hand-held spectroscopic tools and several recent bench top Raman studies, and using a robust selection of well-characterized ancient bone samples, it is demonstrated here that rapid (30 s), non-destructive assessment by means of 1064 nm Raman spectroscopy can provide a field-deployable means by which to quantify bone collagen content. Specifically, it was found that the 1450 cm−1 to 960 cm−1 peak height ratio can provide quantitative estimates of bone collagen content with an error of ±2.8 wt%, and those samples with ratios of greater than 0.1 are uniformly suitable for analysis. Hand-held Raman spectroscopic technology has therefore evolved to the point where field deployment by archaeologists and forensic scientists would be both justified and worthwhile. •Bone collagen is central to a suite of archaeometric analyses.•Such analyses are expensive and time consuming.•We test the ability to quantify bone collagen using handheld Raman spectroscopy.•1450 cm−1 to 960 cm−1 peak height ratio is found to predict bone collagen content.•Raman spectroscopy can rapidly and non-destructively quantify bone collagen content

Survey of medical ethnobotanicals for dental and oral medicine conditions and pathologies

Ethnomedical questionnaires were distributed in Chicago, Costa Rica, and Colombia to identify the most common over-the-counter (OTC) plant or plant-based products advocated for treating oral pain, ulcerative conditions, and cancer within these locations. Over 100 plants or plant-based herbal preparations and commercial products, purchased from local botanical markets and pharmacies, were advocated for the treatment of oral medicine conditions. Locally familiar and common language names were attributed to the plant products at the time of purchase. Plant products or plant-based commercial products containing plant-based essential oils, anesthetic constituents, and or chemical compounds recommended as OTC oral medicine preparations were systematized, tabulated, and correlated with the published phytotherapeutic literature. Though pharmacognostic research is available for some of the species collected, further ethnographic research is needed to correlate common names with the accurate taxonomic identification for each plant species. Furthermore, epidemiological research is needed to verify the use and standardized dosage for OTC ethnomedicine preparations for oral medicine conditions. Pharmacognostic research and clinical trails which can verify taxonomy, dose, safety, active principles, and efficacy of these OTC oral medicine products must be enhanced in order to verify the claimed validity in contemporary, global, oral medicine practice

Photodynamic Therapy: Occupational Hazards and Preventative Recommendations for Clinical Administration by Healthcare Providers

Objective: Photodynamic therapy (PDT) as a medical treatment for cancers is an increasing practice in clinical settings, as new photosensitizing chemicals and light source technologies are developed and applied. PDT involves dosing patients with photosensitizing drugs, and then exposing them to light using a directed energy device in order to manifest a therapeutic effect. Healthcare professionals providing PDT should be aware of potential occupational health and safety hazards posed by these treatment devices and photosensitizing agents administered to patients. Materials and methods: Here we outline and identify pertinent health and safety considerations to be taken by healthcare staff during PDT procedures. Results: Physical hazards (for example, non-ionizing radiation generated by the light-emitting device, with potential for skin and eye exposure) and chemical hazards (including the photosensitizing agents administered to patients that have the potential for exposure via skin, subcutaneous, ingestion, or inhalation routes) must be considered for safe use of PDT by the healthcare professional. Conclusions: Engineering, administrative, and personal protective equipment controls are recommendations for the safe use and handling of PDT agents and light-emitting technologies

Application of Immunohistochemical Staining to Detect Antigen Destruction as a Measure of Tissue Damage

Electrocautery and directed energy devices (DEDs) such as lasers, which are used in surgery, result in tissue damage that cannot be readily detected by traditional histological methods, such as hematoxylin and eosin staining. Alternative staining methods, including 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to stain live tissue, have been reported. Despite providing superior detection of damaged tissue relative to the hematoxylin and eosin (H&E) method, the MTT method possesses a number of drawbacks, most notably that it must be carried out on live tissue samples. Herein, we report the development of a novel staining method, “antigen destruction immunohistochemistry” (ADI), which can be carried out on paraffin-embedded tissue. The ADI method takes advantage of epitope loss to define the area of tissue damage and provides many of the benefits of live tissue MTT staining without the drawbacks inherent to that method. In addition, the authors provide data to support the use of antibodies directed at a number of gene products for use in animal tissue for which there are no species-specific antibodies commercially available, as well as an example of a species-specific direct antibody. Data are provided that support the use of this method in many tissue models, as well as evidence that ADI is comparable to the live tissue MTT method